Table of Contents

1. What’s MEANStack?
2. MEAN explanation
3. MongoDB
4. Express
5. Angular
   1. PrimeNG
6. Node.js
7. Javascript everywhere paradigm
8. How MEANStack works?
9. Backend
10. Frontend
11. Acknowledgements

What’s MEANStack?

This is a template project that implements the MEAN stack. The acronym MEAN stands for (M)ongoDB, (E)xpress, (A)ngular and (N)ode.js. This is a full Javascript stack so both backend and frontend are written in the same language. Furthermore, the project is production-ready thanks to the use of the Docker engine which allows a fast and scalable deployment. And last but not least this stack is fully open source, which means that many developers work every day on all these components.

MEAN explanation

MongoDB

MongoDB is a document-oriented NoSQL database that uses JSON-like document called BSON (Binary JSON). MongoDB use collections and documents: documents consist of key-value pairs which are the basic unit of data in MongoDB. Collections contain sets of documents and function which is the equivalent of relational database tables. These features allow MongoDB to be used for high volume data storage.

Express

Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications. Express has a myriad of HTTP utility, methods and middleware used to create a robust API quickly and easily. Express provides a thin layer of fundamental web application features, without obscuring Node.js, for this reasons it’s the standard framework used on it.

Angular

Angular is a development platform, built on TypeScript. As a platform, Angular include a component-based framework for building scalable web applications and a collection of well-integrated libraries that cover a wide variety of features, including routing, forms management, client-server communication, and more. Angular also has a suite of developer tools to help the development, build, test, and maintenance of the code. Angular offers the advantage of a platform that can scale from single-developer projects to enterprise-level applications.

PrimeNG

PrimeNG is a rich set of open-source native Angular UI components. The project has been developed using PrimeNG components, it’s very simple to use and all the components are very well designed graphically. PrimeNG was chosen thanks to its huge variety of components, so it offers a quick way to create or modify the pages using it. Visit PrimeNG to find out more and check the official repository.

Node.js

Node.js is an open-source, cross-platform, backend Javascript runtime environment that runs on the V8 engine and executes Javascript code outside a web browser. Node.js lets developers use Javascript to write command-line tools for server-side scripting and running scripts server-side to produce dynamic web page content before the page is sent to the user’s web browser.

Javascript everywhere paradigm

Node.js is a representation of the JavaScript everywhere paradigm that means unifying web application development around a single programming language, rather than different languages for server-side and client-side scripts. Such as Node.js the MEAN stack aims to use Javascript in the whole development.

How MEANStack works?

MEANStack is a boilerplate which consists in a template web application that shows the interactions between all the MEAN stack components. The project is divided into backend and frontend, both parts are production-ready and can be simply deployed using the Docker engine. Both backend and frontend have a docker-compose.yaml file in their root directory, the dockers are based on a node:latest docker image and work using pm2-runtime. PM2 is a daemon process manager that helps to manage and keep applications online and automatically allows the cluster mode to run multi-thread processes.

Backend

The backend provides APIs callable only by the frontend thanks to the CORS policy implementation. The APIs are handled by the routing module that is divided into sub-modules. The sub-modules interact with the MongoDB models that create the connections and are defined by a schema-model. The user model describes a simple user schema with only a username and a password. The entity schema is defined with only id and data, this structure allows to insert every not-defined object in data without change the schema. N.B.: This is not a good practice but allows a very fast implementation

To start the backend service it is necessary to create a .env file in the backend folder and define the MongoDB variables, backend and frontend ports and the comma-separated CORS origins. Note that in production it is necessary to insert in the FRONTEND_ORIGINS variable the domain name of the site ( Example: FRONTEND_ORIGINS=domain-site.com,another-domain-site.com).

# This is an example of the backend .env file
PORT=8888
MONGO_INITDB_ROOT_USERNAME=admin
MONGO_INITDB_ROOT_PASSWORD=password
MONGO_INITDB_DATABASE=db_name
FRONTEND_ORIGINS=localhost,127.0.0.1
FRONTEND_PORT=4200

Frontend

The frontend consists in a few pages and simple interactions with the backend: user registration/login features and the entity inserting and reading features. To frontend has two Dockerfile that can be defined in the docker-compose.yaml. The default is Dockerfile.dev that only serve the Angular application and it can be used in development since it does not allow connection from external hosts. To deploy the frontend in production it is necessary to replace the Dokerfile.dev with Dockerfile in docker-compose.yaml. To define the environment variables it is necessary to change the frontend/src/environment/environment.ts and frontend/src/environment/environment.prod.ts and to create a .env file in the frontend folder.

// environment.ts
export const environment = {
  production: false,
  BACKEND_IP: '127.0.0.1',
  BACKEND_PORT: 8888
};

// environment.prod.ts
export const environment = {
  production: true,
  BACKEND_IP: '127.0.0.1',
  BACKEND_PORT: 8888
};

# This is an example of the frontend .env file
PORT=4200
BACKEND_IP=localhost
BACKEND_PORT=8888

Note that in the above example the BACKEND_IP in .env is defined as localhost, because the frontend works with a proxy. The proxy redirects the requests made to the frontend that contains the /api base endpoint to the backend ( localhost in development). The development proxy configurations are stored in the frontend/config/proxy.config.json. Instead, in case of production, it is necessary to change the BACKEND_IP defined in the environment.prod.ts with the effective backend IP. When in production the proxy requests are handled by nginx, this because in production once the Angular build is completed the dist folder is moved to an nginx:latest docker container and is defined as a proxy through the nginx-proxy.conf.

Acknowledgements

This project is not completed, we are working to improve both flexibility and security of the components. We hope that this template can help someone to create, develop and deploy his project in a fast way and without worrying to create from zero the components and their interactions.